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BUSINESS COMBINATIONS - Additional Information (Details) - business | 9 Months Ended
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Sep. 30, 2019 | Sep. 30, 2018
Business Acquisition [Line Items] |  |
Number of businesses acquired | 8 |
Minimum |  |
Business Acquisition [Line Items] |  |
Useful life of finite lived intangible assets | 5 years |
Maximum |  |
Business Acquisition [Line Items] |  |
Useful life of finite lived intangible assets | 10 years |
Eastern | Tuck-in Solid Waste Collection |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 3 |
Eastern | Solid Waste Collection, Transfer and Processing |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired |  | 1
Western | Tuck-in Solid Waste Collection |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 3 |
Western | Solid Waste Collection, Transfer and Recycling |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 1 |
Western | Solid Waste Hauling and Transfer Assets |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired | 1 |
Western | Solid Waste Collection |  |
Business Acquisition [Line Items] |  |
Number of businesses acquired |  | 3

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- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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